The present invention relates to a thermoelectric conversion component adapted to perform cooling and heat generation by means of the Peltier effect as well as thermal power generation by means of the Seebeck effect.
A thermoelectric conversion component (although it is referred to also as a Peltier component or an electronic cooling device, etc., it is called so in the meaning of including them) is generally constituted by a p-type thermoelectric material chip and an n-type thermoelectric material chip sandwiched between two substrates so that the p-type thermoelectric material chip and the n-type thermoelectric chip are placed in a pn junction through a conductive substance such as a metal.
The conventional thermoelectric conversion component as mentioned above has a temperature detecting unit such as a thermistor or the like mounted on the substrate by adhesion or the like so that input/output electrodes of the temperature detecting unit are connected to an external control device through lead wires or the like, in order to detect and control the temperature of the two substrates.
The conventional thermoelectric conversion components described above have required mounting of a temperature detecting unit, such as a thermistor, etc. on the substrate in order to perform accurate detection and control of temperatures. This necessitates the provision of a space or area for mounting the temperature detecting unit on the substrate of the thermoelectric conversion component. At the same time, consideration has to be given to the influence of a thermal capacity of the temperature detecting unit. There has been a problem in that the thermoelectric conversion component requires a performance specification that is higher than that inherently required. Further, where the thermoelectric conversion component is used as a cooling component, an input electrode therefor is provided on a substrate of a heat radiating side in order not to become a load against cooling. Meanwhile, the temperature detecting unit such as a thermistor is generally attached to the substrate of the cooling side. In such a case, there has been a problem that external heat comes by conduction through lead wires connecting between the temperature detecting unit and an external control device, thereby increasing the load against cooling.
Further, since the structure like this requires a complicated process of connecting between the temperature detecting unit and the external control device, and also connecting between cubic structural bodies during so-called mounting process. It is therefore difficult to say, for the conventional thermoelectric conversion component, to be preferable also in respect of cost and yield.
The above-mentioned problem is prominent particularly for a small-sized thermoelectric conversion component. For example, a semiconductor laser utilized for optical communications requires cooling by a thermoelectric conversion component, because it generates heat. However, since the thermoelectric conversion component is small in size, i.e. a several-mm square, the mounting of a sensor or the like for temperature control has great influence on the size and cooling performances. Accordingly, there has been a problem in respect of reducing, as a whole, the size and the power consumption.